Nanoparticles existed before nanotechnology.
Every time a volcano roars, carbon nanotubes and fullerenes are formed.
This happens as well when forests,
Or oil, burn.
The thermodegradation of organic matter generates nanostructures
And, indeed, biological processes involve nanoparticles,
Such as magnetosomes, which function as bacterian compasses,
Or ferritin, an iron reserve.
Sometimes humans have taken advantage of nanoparticles without knowing it.
A proof o this are the traces of pigments found in the alveoli of 5000-year-old mummies,
Nanometric titanium dioxide used presumably in tattoos,
Nanoparticles produced spontaneously when mixing oil and natural clay.
Or spontaneously when mixing of aluminosilicates and metallic salts at high temperatures,
AS it happens in the stained-glass windows of churches
Where, for instance, yellow is made of nanoparticles of non-radioactive uranium oxide.